The present invention relates to a novel apparatus for leveling a vehicle lamp. More particularly, the present invention relates to a technique for facilitating the coupling of an adjusting rod and a slanting member together in a leveling apparatus in order to improve efficiency in coupling both of them together and also prevent the deformation of and damage to a coupling member.
Some vehicle lamps, for example, automobile head lamps are equipped with a leveling function, that is, the function of correcting an irradiating direction every time that direction is biased upward or downward because the number of passengers on board or the weight of loaded goods varies.
Such a head lamp normally comprises a leveling mechanism fixed to a vehicle body or a vehicle-body-side member, the leveling mechanism including an adjusting rod which is moved back and forth by a proper driving device, and a coupling member which is provided in a head lamp unit or in the slanting end portion of the slanting member of a reflector and coupled to the front end portion of the adjusting rod, so that the slanting member is slanted/tilted upward or downward by moving the adjusting rod back and forth.
FIG. 1 is a schematic diagram showing an example 100 of a vehicle head lamp having the leveling mechanism.
In FIG. 1, 101 represents a head lamp unit whose back side is supported at three points of a vehicle body (not shown), and these three support points are positioned so that two of them are situated in two places which are closer to upper end of the head lamp unit 101, and properly separated from each other in the lateral/horizonal direction, the remaining one being perpendicularly separated downward from one of the two support points in the respective two places.
With a line defined by connecting the two support points (not shown) separated from each other in the horizontal direction closer to the upper end out of the three support points as a slanting axis c, the head lamp unit 101 is slanted/tilted by longitudinally moving the remaining support point (hereinafter called "leveling point"), which will be described later.
The lower end portion of the head lamp unit 101 is protruded downward and a pivot receiving body 103 is mounted on that protruded portion. A backwardly-open spherical recessed portion 104 is formed in the pivot receiving body 103.
Further, in FIG. 1, 105 represents a leveling mechanism fixed to the vehicle body, and a driving mechanism (not shown) is provided in its casing 106. A piston rod 107 axially extending in the longitudinal direction is provided so as to be axially moved by the driving mechanism, and a spherical pivot body 108 to be fitted into the spherical recessed portion 104 is formed in the front end portion of the piston rod 107. The pivot body 108 is pivotally inserted into the spherical recessed portion 104 of the pivot receiving body 103, whereby the lower-side support point among the aforesaid three support points, that is, a leveling point is defined.
More specifically, as shown in FIGS. 1 and 2, the pivot receiving body 103 forms a substantially cylindrical body with one end opening, and its inner surface forms the spherical recessed portion 104. The open mouth 109 is smaller in diameter than the spherical recessed portion 104, and three slits 111, 111, 111 parallel to each other are axially formed in the peripheral wall 110 of the pivot receiving body 103, whereby elastic pieces m, m, m having elasticity in a direction perpendicular to the axis in the open-end-side portion of the peripheral wall 110 of the pivot receiving body 103.
As shown in FIG. 3, when the pivot body 108 is inserted into the pivot receiving body 103, the pivot body 108 is put to the open mouth 109 of the pivot receiving body 103 while the axis of the pivot body 108 and that of the pivot receiving body 103 are kept aligned and then pressed into the spherical recessed portion 104.
Then the elastic pieces m, m, m of the peripheral wall 110 are elastically bent outward as the pivot body 108 is fitted in. As a result, the diameter of the open mouth 109 of the pivot receiving body 103 is enlarged and the pivot body 108 is inserted into the spherical recessed portion 104, as shown in FIG. 4.
The elastic pieces m, m, m of the peripheral wall 110 are restored to the original condition after the pivot body 110 is inserted into the pivot receiving body 103, whereby the pivot body 108 is pivotally received into the spherical recessed portion 104 of the pivot receiving body 103 and prevented from slipping off the spherical recessed portion 104.
When the piston rod 107 is moved, the lower protruded portion of the head lamp unit 101 is substantially longitudinally moved, so that the head lamp unit 101 is slanted with the slanting axis c as a slanting center. Thus, the irradiating direction of the head lamp unit 101 is vertically adjusted.
With the vehicle head lamp 100 like this, the elastic pieces m, m, m of the pivot receiving body 103 are always required to be bent when the pivot body 108 is inserted into the pivot receiving body 103 and since the pivot body 108 is inserted into the pivot receiving body 103 against the elastic force of the elastic pieces m, m, m, pressing force needs applying to a certain extent. Moreover, the pivot receiving body 103 will fail to follow the movement of the piston rod 107 unless the elastic force of the elastic pieces m, m, m is kept greater to some degree in order to prevent the piston rod 107 from backlashing after the pivot body 108 has been inserted.
Therefore, it is inevitable to conduct the coupling operation with a certain amount of strong force when the pivot body 108 is inserted into the pivot receiving body 103, so that the coupling operation therebetween is not easy.
The pivot body 108 and the pivot receiving body 103 are not always coupled together in such a state that the axes of them are kept aligned and if the axes of them are slightly shifted from each other, greater force must be applied to the shifted elastic piece 112 and them there is a possibility that the elastic piece 112 may be deformed or damaged. This is a problem.